Now, to unlock disease secrets bacterial colonies sculpted into custom shapes by a 3D printer could be a key to understanding how some antibiotic-resistant infections develop. The new technique uses methods similar to those employed by commercial 3D printers, which extrude plastic, to create gelatin-based bacterial breeding grounds. These microbial condos can be carved into almost any three-dimensional shape, including pyramids and nested spheres.

This 3D-printing technique could be used to investigate questions like "how many bacteria have to be clustered together, and in what size and what shape, in order for that microcolony to start acting differently than the cells do on their own," said study researcher Jason Shear, a professor of chemistry and biochemistry at the University of Texas at Austin.